A track-type mobile machine utilizes tracks located at either side of the machine to propel the machine. The tracks include chains having links pinned end-to-end to form a loop that extends around a drive sprocket and one or more idler wheels, and ground engaging elements known as track shoes connected to each pair of links in the chains. A track shoe, together with a pair of links, is known as a track pad. In some configurations, the track pad is a single integral component. The sprocket is driven by an engine of the machine to rotate the chains and push the track pads against a work surface, thereby transmitting torque from the engine to the surface in opposition to a desired travel direction of the machine.
Over time, the track pads wear, creating slack in the chains between the sprocket and the idler wheel(s). This slack, if unaccounted for, can cause the chains to wear excessively, break, and/or to slip off the drive sprocket and idler wheel(s). When this occurs, the machine is pulled out of service for a time and labor-intensive service operation. In some instances, replacement parts are not available at the time of track failure, thereby creating even more downtime while waiting for parts to be ordered and shipped to the service facility. Accordingly, it can be important to periodically monitor track pad wear, so that the appropriate parts can be procured in time for servicing and so that service can be performed before failure occurs.
One attempt to provide for wear monitoring is disclosed in U.S. Pat. No. 6,533,371 that issued to Hori et al. on Mar. 18, 2003 (“the '371 patent). Specifically, the '371 patent discloses a shoe for the crawler belt of a track-laying vehicle. The shoe is directly fixed to links of the crawler belt by means of bolts. The different links are connected end-to-end by pins, and the crawler belt is driven through engagement of the pins with a sprocket. The ground face of the shoe has grooves, each of which is provided with a wear indicator that provides an indication of a wear limit of the shoe. With this configuration, the wear limit of the shoe can be understood at a glance, and the wear indicator serves as an index of right timing for replacement of the shoe.
While the wear indicators of the '371 patent may help to determine when the ground surface of a track shoe is worn, it may be less than optimal. In particular, depending on the size of the track-laying vehicle and/or its application, it may be possible for the links of the crawler belt to wear at a greater rate than the track shoes. And, in these situations, the wear indicators of the '371 patent would not provide sufficient indication of an impending failure. In addition, these wear indicators may only provide an indication of when the track shoe is completely worn and needs to be replaced. This may not give enough warning for parts to be ordered and service to be scheduled in advance of failure.
The disclosed wear monitoring system is directed to overcoming one or more of the problems set forth above.